Carbon Nanohorns/Pt Nanoparticles/DNA Nanoplatform for Intracellular Zn2+ Imaging and Enhanced Cooperative Phototherapy of Cancer Cells

Engineering carbon-based nanomaterials for the delivery of platinum compounds: An innovative cancer disarming frontier

Carbon-based nanomaterials have been frequently used as one of the most advanced and fascinating nanocarriers for drug delivery applications due to their unique physicochemical properties. Varying types of carbon nanomaterials (CNMs) including carbon nanotubes, graphene, graphene oxides, carbon nanohorns, fullerenes, carbon nanodots, and carbon nanodiamonds are promising candidates for designing novel systems to deliver platinum compounds. CNMs modification with various moieties renders vast bio-applications in the area of targeted and organelle-specific cancer therapy. This review featured an updated and concise summarizations of various types of CNMs, their synthesis, advantages and disadvantages including potential bio-toxicity for biomedical applications. The therapeutic utility of CNMs and their efficacy have been noticed and for the first time, this review addressed CNMs-focused applications on the delivery of platinum-derivatives to the cancer site. Collectively, the contents of this review will assist researchers to focus on the possible fabrication, bio-functionalization and designing methods of CNMs to the further development of their future biomedical implementations.

Biomedical Utility of Non-Enzymatic DNA Amplification Reaction: From Material Design to Diagnosis and Treatment

Nucleic acid nanotechnology has become a promising strategy for disease diagnosis and treatment, owing to remarkable programmability, precision, and biocompatibility. However, current biosensing and biotherapy approaches by nucleic acids exhibit limitations in sensitivity, specificity, versatility, and real-time monitoring. DNA amplification reactions present an advantageous strategy to enhance the performance of biosensing and biotherapy platforms. Non-enzymatic DNA amplification reaction (NEDAR), such as hybridization chain reaction and catalytic hairpin assembly, operate via strand displacement. NEDAR presents distinct advantages over traditional enzymatic DNA amplification reactions, including simplified procedures, milder reaction conditions, higher specificity, enhanced controllability, and excellent versatility. Consequently, research focusing on NEDAR-based biosensing and biotherapy has garnered significant attention. NEDAR demonstrates high efficacy in detecting multiple types of biomarkers, including nucleic acids, small molecules, and proteins, with high sensitivity and specificity, enabling the parallel detection of multiple targets. Besides, NEDAR can strengthen drug therapy, cellular behavior control, and cell encapsulation. Moreover, NEDAR holds promise for constructing assembled diagnosis-treatment nanoplatforms in the forms of pure DNA nanostructures and hybrid nanomaterials, which offer utility in disease monitoring and precise treatment. Thus, this paper aims to comprehensively elucidate the reaction mechanism of NEDAR and review the substantial advancements in NEDAR-based diagnosis and treatment over the past five years, encompassing NEDAR-based design strategies, applications, and prospects.

Pt-Se-Bonded Nanoprobe for High-Fidelity Detection of Non-small Cell Lung Cancer and Enhancement of NIR II Photothermal Therapy

Non-small cell lung cancer (NSCLC) accounts for a high proportion of lung cancer cases globally, but early detection remains challenging, and insufficient oxygen supply at tumor sites leads to suboptimal treatment outcomes. Therefore, the development of core-shell Au@Pt-Se nanoprobes (Au@Pt-Se NPs) with peptide chains linked through Pt-Se bonds was designed and synthesized for NSCLC biomarker protein calcium-activated neutral protease 2 (CAPN2) and photothermal therapy (PTT) enhancement. The NP can be specifically cleaved by CAPN2, resulting in fluorescence recovery to realize the detection. The Pt-Se bonds exhibit excellent resistance to biologically abundant thiols such as glutathione, thus avoiding "false-positive" results and enabling precise detection of NSCLC. Additionally, the platinum (Pt) shell possesses catalase-like properties that catalyze the generation of oxygen from endogenous hydrogen peroxide within the tumor, thereby reducing hypoxia-inducible factor-1α (HIF-1α) levels and alleviating the hypoxic environment at the tumor site. The Au@Pt-Se NPs exhibit strong absorption bands, enabling the possibility of PTT in the near-infrared II region (NIR II). This study presents an effective approach for the early detection of NSCLC while also serving as an oxygen supplier to alleviate the hypoxic environment and enhance NIR II PTT.

Functional DNA sensors integrated with nucleic acid signal amplification strategies for non-nucleic acid targets detection

In addition to carrying and transmitting genetic material, some DNA molecules have specific binding ability or catalytic function. DNA with this special function is collectively referred to as functional DNA (fDNA), such as aptamer, DNAzyme and so on. fDNA has the advantages of simple synthetic process, low cost and low toxicity. It also has high chemical stability, recognition specificity and biocompatibility. In recent years, fDNA biosensors have been widely investigated as signal recognition elements and signal transduction elements for the detection of non-nucleic acid targets. However, the main problem of fDNA sensors is their limited sensitivity to trace targets, especially when the affinity of fDNA to the targets is low. To further improve the sensitivity, various nucleic acid signal amplification strategies (NASAS) are explored to improve the limit of detection of fDNA. In this review, we will introduce four NASAS (hybridization chain reaction, entropy-driven catalysis, rolling circle amplification, CRISPR/Cas system) and the corresponding design principles. The principle and application of these fDNA sensors integrated with signal amplification strategies for detection of non-nucleic acid targets are summarized. Finally, the main challenges and application prospects of NASAS integrated fDNA biosensing system are discussed.

Dual-ratiometric electrochemical aptasensor based on carbon nanohorns/anthraquinone-2-carboxylic acid/Au nanoparticles for simultaneous detection of malathion and omethoate

Organophosphorus pesticides (OPs) are one of the most frequently used pesticides in agriculture, and their residues in environment have caused serious human health and environmental concerns. In this work, we reported a dual-ratiometric electrochemical aptasensor based on carbon nanohorns/anthraquinone-2-carboxylic acid/Au nanoparticles (CNHs/AQ/AuNPs) for simultaneous detection of malathion (MAL) and omethoate (OMT). Here, CNHs/AQ/AuNPs composites were synthesized by a simple room temperature method, and used as a substrate to generate a reference signal (I_AQ) and enlarge response signals. Hairpin DNA was then immobilized, offering independent and specific binding sites to further adsorb MB-labelled MAL aptamer (MB-Apt1) and Fc-labelled OMT aptamer (Fc-Apt2). Upon the addition of MAL or OMT, the formation of aptamer-target complex caused the release of MB-Apt1 or Fc-Apt2 from the electrode, resulting in a decrease in I_MB or I_Fc, while I_AQ kept unchanged. Based on this principle, the ratiometric signals of I_MB/I_AQ and I_Fc/I_AQ were used to simultaneously detect MAL and OMT, offering a linear range of 3 pg mL^-1 to 3 ng mL^-1 for MAL and 10 pg mL^-1 to 10 ng mL^-1 for OMT, and no significant cross-reactivity existed. By taking advantage of the excellent conductivity and large specific area of CNHs/AQ/AuNPs and the stable two-dimensional structure of hairpin DNA, the aptasensor exhibited high sensitivity, selectivity and reliability. Our work has offered a novel way for simultaneous detection of multiple OPs.

Carbonaceous Nanomaterials for Phototherapy of Cancer

Carbonaceous nanomaterials (CNMs) have drawn tremendous biomedical research interest because of their unique structural features. Recently, CNMs, namely carbon dots, fullerenes, graphene, etc, have been successful in establishing them as considerable nanotherapeutics for phototherapy applications due to their electrical, thermal, and surface properties. This review aims to crosstalk the current understanding of CNMs as multimodal compounds in photothermal and photodynamic therapies as an integrated approach to treating cancer. It also expounds on phototherapy's biomechanics and illustrates its relation to cancer biomodulation. Critical considerations related to the structural properties, fabrication approaches, surface functionalization strategies, and biosafety profiles of CNMs have been explained. This article provides an overview of the most recent developments in the study of CNMs used in phototherapy, emphasizing their usage as nanocarriers. To conquer the current challenges of CNMs, we can raise the standard of cancer therapy for patients. The review will be of interest to the researchers working in the area of photothermal and photodynamic therapies and aiming to explore CNMs and their conjugates in cancer therapy.

Hierarchical Composite Nanoarchitectonics with a Graphitic Core, Dendrimer and Fluorocarbon Domains, and a Poly(ethylene glycol) Shell as O2 Reservoirs for Reactive Oxygen Species Production

Graphene oxide (GO), single-walled carbon nanohorn (CNHox), and nitrogen-doped CNH (N-CNH) were functionalized with fluorinated poly(ethylene glycol) (F-PEG) and/or with a fluorinated dendrimer (F-DEN) to prepare a series of assembled nanocomposites (GO/F-PEG, CNHox/F-PEG, N-CNH/F-PEG, N-CNH/F-DEN, and N-CNH/F-DEN/F-PEG) that provide effective multisite O₂ reservoirs. In all cases, the O₂ uptake increased with time and saturated after 10-20 min. When graphitic carbons (GO and CNHox) were coated with F-PEG, the O₂ uptake doubled. The O₂ loading was slightly higher in N-CNH compared to CNHox. Notably, coating N-CNH with F-DEN or F-PEG, or with both F-DEN and F-PEG, was more effective. The best performance was obtained with the N-CNH/F-DEN/F-PEG nanocomposite. The O₂ uptake kinetics and mechanisms were analyzed in terms of the Langmuir adsorption equation based on a multibinding site assumption. This allowed the precise determination of multiple oxygen binding sites, including on the graphitic structure and in the dendrimer, F-DEN, and F-PEG. After an initial rapid, relatively limited release, the amount of O₂ trapped in the nanomaterials remained high (>95%). This amount was marginally lower for the functionalized composites, but the oxygen stored was reserved for longer times. Finally, it is shown that these systems can generate singlet oxygen after irradiation by a light-emitting diode, and this production correlates with the amount of O₂ loaded. Thus, it was anticipated that the present nanocomposites hierarchically assembled from components with different characters and complementary affinities for oxygen can be useful as O₂ reservoirs for singlet oxygen generation to kill bacteria and viruses and to perform photodynamic therapy.

A DNAzyme-based normalized fluorescence strategy for direct quantification of endogenous zinc in living cells

Taking the maximum fluorescence of an identical fluorophore as a reference, a DNAzyme-based normalized strategy is developed to unify the output signals under external interferences. This makes it possible to directly quantify endogenous zinc in living cells by in situ fluorescence imaging, implying promising potential in fundamental study and early disease diagnosis.

Sustainable Carbon Materials toward Emerging Applications

It is desirable for a sustainable society that the production and utilization of renewable materials are net-zero in terms of carbon emissions. Carbon materials with emerging applications in CO₂ utilization, renewable energy storage and conversion, and biomedicine have attracted much attention both academically and industrially. However, the preparation process of some new carbon materials suffers from energy consumption and environmental pollution issues. Therefore, the development of low-cost, scalable, industrially and economically attractive, sustainable carbon material preparation methods are required. In this regard, the use of biomass and its derivatives as a precursor of carbon materials is a major feature of sustainability. Recent advances in the synthetic strategy of sustainable carbon materials and their emerging applications are summarized in this short review. Emphasis is made on the discussion of the original intentions and various sustainable strategies for producing sustainable carbon materials. This review provides basic insights and significant guidelines for the further design of sustainable carbon materials and their emerging applications in catalysis and the biomedical field.

Green Approaches to Carbon Nanostructure-Based Biomaterials

The family of carbon nanostructures comprises several members, such as fullerenes, nano-onions, nanodots, nanodiamonds, nanohorns, nanotubes, and graphene-based materials. Their unique electronic properties have attracted great interest for their highly innovative potential in nanomedicine. However, their hydrophobic nature often requires organic solvents for their dispersibility and processing. In this review, we describe the green approaches that have been developed to produce and functionalize carbon nanomaterials for biomedical applications, with a special focus on the very latest reports.